Lima, Peru ? Peruvian rescuers were working Monday to evacuate the bodies of three young American mountaineers from a 100-foot-deep crevasse in the Andes mountains. Kristen Yoder, 21, her brother Dustin Yoder, 23, and Brennan Larson, 24, died during their icy climb high on the Artesonraju peak, police said.

Police Maj. Edmundo Vidal, of the High Mountain Rescue Unit, said recovering the bodies down the long descent was expected to last into the night. The three climbers went missing last week about 2,000 feet from the 19,682-foot summit of the glacier-covered mountain in the Cordillera Blanca range.

Authorities said the three climbers were on a fairly treacherous route without a guide. Vidal said the trio may not have used the proper safety techniques.

“Given their ages, 21 or 22 years old, I doubt they had a lot of experience,” he said.